[PRQ#44538] Deletion Request for cython3

MarsSeed [1] filed a deletion request for cython3 [2]: This is not needed anymore; repo carries cython3 as: https://archlinux.org/packages/extra/x86_64/cython-dev/ [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/cython3/